(a) Technical Field of the Invention
The present invention relates to an inflatable head restraint device for a vehicle seat, and in particular, a device for restraining the head and neck and backbone portion of an occupant, preventing injury to the head and neck from either rear, front or side impacted crash.
(b) Description of the Prior Art
The head restraint device developed by SAAB makes use of a linking rod connected to a trigger board on the seat back. When a rear impact happens to the car, the trigger board will be pushed backward by the jolt of occupant's body which moves the headrest downward to hold the head portion of a passenger to minimize injuries. The WHIPS device developed by Volvo makes use of pendulum-like backward and downward moment of the headrest and the seat back, and in particular the headrest will be moved backward to hold the head of the passenger so as to minimize the impact force exerted to the neck portion. The backward movement of the seat back and the headrest is in two stages. First, the parallel backward movement of the sea back and the headrest, and then the seat back will be slightly tilted at the second stage. However, the head restraint of those conventional designs provides only the buffering protection to the head for rear impact. There is still lack of protection for head and neck from all aspects to the front, rear or lateral impact. Accordingly, it is an object of the present invention to provide a head restraint device for a vehicle seat, which mitigates the above drawbacks.